Bacterial protein mimics its host to disable a key enzyme

Bacteria use all sorts of cunning to trick hosts into doing their bidding. One con in their bag of tricks: the molecular mimic. In this ruse, bacteria or their agents look for all purposes like some native molecule in a cell, but then do not behave accordingly. Working with H. pylori, the bacterium responsible for gastric ulcers and cancer, researchers have revealed one way bacteria pull this off, deciphering the structure of a piece of CagA, a bacterial protein that impersonates a human protein in order to disable a key enzyme.